Various configurations of internal combustion rotary engines are known and have varying degrees of complexity. Rotary engines typically use a solid, usually triangular, rotor, or a rotor having vanes therein. The rotor rotates either coaxially in a cooperating casing, or may be mounted eccentrically therein with varying-volume working zones for intake, compression, expansion, and exhaust being defined by variously configured chambers between the perimeter of the rotor and the inner surface of the casing.
Efficiency and maximum operating speed of these engines are limited by the various configurations thereof due to vibration, lubrication, and cooling considerations for example.